Abstract: The generation of acid rain precursors, i.e., SO.sub.x and NO.sub.x, and slag during the combustion of a carbonaceous fuel, e.g., coal, is counteracted in a slagging combustor apparatus and process. The fuel is combusted in a primary combustor under substoichiometric combustion conditions and at a temperature greater than the fuel's ash fusion temperature. The substoichiometric combustion conditions suppress the formation of NO.sub.x. Most of the noncombustibles are separated from the gaseous products of combustion, in the form of liquid slag, to form treated gaseous combustion products having a noncombustible content that is substantially reduced with respect to the noncombustible content of the fuel. The temperature of the treated gaseous combustion as it leaves the primary combustion is above the ash fusion tmeprature of the fuel. A sorbent is introduced into the treated gaseous combustion products and calcined. The calcined sorbent removes SO.sub.x from the treated gaseous combustion products.

Abstract: In the operation of a slagging combustor, including an apertured baffle defining part of a cylindrical combustion chamber having a head end which includes a nozzle for injection of sulfur-containing particulate carbonaceous material to be combusted in a whirling oxidant flow field, there is injected a particulate sulfur sorbent at the aperture of the baffle towards the nozzle to react with released sulfur. The sulfur sorbent is injected into the combustion zone from a location near the exit end thereof. Fuel is injected near the center of the head end. A relatively fuel-rich recirculation zone is established and maintained along the longitudinal axis of the combustion chamber surrounded by a relatively oxygen-rich annular region.

Abstract: A low thrust monopropellant engine having a conventional body and nozzle configuration wherein the monopropellant fuel is fed into the thruster with dual injection tubes via an injector shell with dual spray jets formed therein. The spray jets are positioned generally opposed to each other. A heater-screen pack combination thermally decomposes the fuel after injection into the combustion chamber of the thruster.